Types of dermoid cyst 1 Sequestration dermoid cyst

Types of dermoid cyst 1 - Sequestration dermoid cyst. 2 - lmplantation dermoid cyst. - Epidermoid cyst. 3 - Tubulodermoid cyst: - Thyroglossal cyst. - Branchial cyst. 4 -Teratomtaous dermoid cyst of the ovary and testis (sacrococcygeal tumor). 5 -lnclusion dermoid.

Sequestration dermoid cyst A congenital cyst. Caused by sequestrated piece of squamous epithelium in the subcutaneous tissue at a line of fusion of the body during fetal life but it appears later in life. Never in the limb

Along the lines of fusion: 1 - Face : external angular (commonest) Or lnternal angular 2 - Ear : post-auricular Or Pre-auricular 3 - Neck : Midline , sublingual, supramyerohyoid (in the froor of the mouth) , lnframyelohyoid or suprasternal 4 - Trunk : in midline

Clinical picture Age : a childhood Complaint : A slowly growing painless subcutaneous swelling

Signs General : Other anomalies. Local: well defined, globular, lax, cystic swelling , not attached to the skin. Transillumination : opaque The underlying bone may be hollowed out pedicle connecting the deep aspect. of the cyst to dura matter.

Complication (infection , rupture , hg , compression , recurrence) 1 -cerebraral compression (dumble shaped) 2 - lntracranial complication with the dura matter should be investigated by skull x-ray before excision to be sure the sutures are closed.

Treatment 1 - Uncomplicated : Surgical excision (best lines of treatment) ) ln children with dermoid cyst in the scalp it is better to wait till closure of the skull sutures because some cysts may communicate with the dura. 2 - lnfected : incision and drainge followed by excision after inflammation subsides.

Implantation dermoid cyst Acquired dermoid cyst. Implantation of skin into subcutaneous tissue by: 1 - Pricking wound on the tip of a finger as during sewing. 2 - Use of skin as graft in hernioplasty.

Diagnosis Type of Patient: Manual worker (tip of finger) Complaint : Slowly growing swelling Signs: Small & tense cystic swellings. The overlying skin is sometimes scarred.

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